Crankshaft chuck



Nov. 16, 1943. w MEYER 2,334,639

CRANKSHAFT CHUCK Filed Sept. 4, 1942 FTEJI INVENTOR. WALTER R.MEYE.R

Patented Nov. 16, 1943 The R." K. Le "Blond Machine Tool Company, Cincinnati, Ohioya corporation of Delaware.

" hpplication septeinber 4, 194a, wallets-t ig 1 thecrankshaft intermediate these end support-,-

ingv members-preferably by means ofthe webs t Y ,of such crankshafts. j More particularly adapted to grip the crankshaft, so located on end centering devices, by means of locating surffaces on the crankshaft web having a predete'r mined relationship to the axis of rotation of the crankshaft and to the work'spindleof the-lathe.

Another'object of this invention is tovprovide in a chucking devicefor lathes means whereby the tightening device maybe operated to effect gripping of the work piece by the chuck withthe simultaneous-application of the work engaging means operating from'fourv different directions toward the center of rotation of the work piece,

' all of said movements being sii'nultaneously 'ef- 'f'ected from a single clamping member. I

Another object of thi's'invention is to provide in a crankshaft chucking device a "pair of fixed workengaging abutments mounted in the chuck body so as to engage the work from substantially perpendicular directions and to provide a si clamping device which simultaneously applies clamping action to the work piece to present it to both'of said fixed abutments with substantially equal pressure by the operation of a single clamping mechanism.

Further features and advantages of this invention will appear from a detailed description of the drawing in which:

Figure I is an axial view of a center drive rin gear chucking device or crankshaft-chuck incorporating the principles of this invention.

Figure II is a diametral cross-section on the line II-II of Figure I through the chucking device, particularly showing the fixed abutments and the clamping member associated therewith.

This invention is shown applied to a typical center drive chuck but may, of course, be applied to any type of machine tool work spindle wherein the work is to be gripped and rotated while performing machining operations thereon. In this particular exemplary showing of the center drive type of chuck or work spindle there is shown the driving gear I which is driven-from usual power transmission mechanism as is typical in center drive work spindles in center drive lathes. The chuck body 2 is fixed to the ring the 'chucking devices is gear and may 'beformed integrally meibrtifim is providedwith a thick. abutment 3 held in place in the ,chuckbodyflby; suitable screwsla; also in this chuck the work engaging abutment 4 having two work engaging. surfaces ,5fand 6 and 7 held in place onlthe chuck by appropriate work piece" or crankshaft 8 to be gripped in the chu'c kin'g'gdevice" has its main axis '9 deg termine'd'jby the usual center holes drilledin'the "e'nids "ofjthe; crankshaft (which is not shown) and located nappropriate centering devicestypic'al ofcenterdrive latheist In this instance-the center holeswhich determine the axis'of rotation f the crankshaft areaccurately machine'd in a predetermined relationship to the exterior porti'ons l8 and I I; of'thecrankshaftweb 8. Similarly the surfaces 3a 'o'f the fixed'locating block '3 and the surfaces 5 and 6 of the locating block 4- are located in a predetermined and similar relationship to the axis ofrotation 9 ofthe'chuckin'g'device; Thus when the crankshaft web fl is placed in the chuck in engagement with the surfaces 3a;= *5,and' I5 of the chucking device the crankshaft web and its main axis' of rotation 9 .will be brought precisely on the axisof rotation Qofthechuckbddyy r a .7 V. i

The crankshaft web 8 in this position is rigidly and positively held against the abutment blocks 3 and 4 by clamping devices comprising a, clamping arm l2 which is mounted on a pivot pin l3, fixed in the chuck body so that it swings to and from the work piece in a direction substantially along the line I4 to forc the crankshaft web 8 toward the work engaging surface 3a of the abutment block 3. Connected to this clamping arm I2 is a link l5 connected by a suitable pivot pin Hi to the arm 12 and connected at its other end to a pin [1 of the bell-crank lever l8 carried on a pivot pin I9 fixed in the chuck body 2. A horizontally projecting arm of the bell-crank 18 has a pin 20 upon whichis mounted the bifurcated clamping member 2| as best seen in Figure II. This clamping member 2| has downwardly extending side arm portions 21a and 2 lb each of which is pivotally' mounted around the end 20 of the bell-crank [8. In the upper portion of this clamping member 2| is the clamping screw 22 which has its lower work engaging abutment portion 22a coming down on top of the surface 23 of the crankshaft web 8 tc-force the crankshaft downwardly in the direction of the line 2| so as to force the web 8 against the abutment surfaces 5 and 6 of the abutment block 4 in the chuck body.

It will, therefore, be obviou that when the 8 that it will tend to force the web against the block 4 and resistance of the block 4 to further movement of the crankshaft web 8 will cause clamping screw 22 is tightened to bring its end 22a down upon the surface 23 of the crankshaft web the clamping member 2| to move upwardly,

swinging the horizontal arm of the bellcrank l8 on its pivot I9 upwardly and causing the link I to move horizontally to the right and thereby move the clamping arm I2 toward the surface 25 0f the crankshaft web forcing this web, atthe crank lever and said first mentioned clamping member whereby moving of said second clampsame time that it is being forced down-against the block 4, against the fixed abutment block 3 of the. chuck body 2. Therefore, by tightenin the,

screw 22 the crankshaft is automatically and simultaneously urged with substantially equal pressure against both the abutment blocks 3 and 4 so as to rigidly support the crankshaft'in the chucking device in proper alignment with the axis 'ofrotation9. t

ing member against a work piece in said chuck automatically efiects the movement of said first Having fully set forth and described my in- V vention what I claim as new an desire to secure byLettersPatentiszl ;1. In' a chucking device, a rotary chuckrbody,

a fixed abutment in said chuckbody located to one side of the axisrofrotationthereof, a second fixed abutment located'to one side of said axis positioned-substantially perpendicular to said first mentioned abutment a clamping member pivotally mountedvon said chuck body for swinging movement to and from one of said abutments, a second clamping memberpivotally mounted on a bell-crank lever mounted on the chuck body, for movement toward said other fixed abutment, and linkage connection means between said bellcifanklever and said first mentioned clamping member whereby moving of said secondclamping member against; awork piecein said chuck automatically effects the movement of said first mentioned clamping member into engagement with said work piece in a direction substantially perpendicular to the clamping action ofsuchsecond mentionedjclamping device.

2;In'a chucking device, a rotary chuck I body,

a fixed abutment in said chuck 'body'located to mentioned clamping member into engagement with said work piece in a direction substantially perpendicular to the clamping action of such second mentioned clamping device, said clamping members being movable to their respective abutments in substantially perpendicular direction to each other.

' 3. In a crankshaft chuck, a rotary chuck body, a fixed abutment in said chuck body located to onejside of the axis of rotation thereof, a, second fixed abutment in said chuck body located sub stantiallyperpendicular to said first mentioned abutment and located to one side of the axis of rotation thereof, a clamping arm pivotally mount ed on said chuck body having a work engaging portion"movablein a direction perpendicular to one of saidfixed abutments, a bell-crank lever pivotally mounted onzsaid chuck body','linkage connections between said clamping arm and said crank lever, a bifurcated clamping device piv- 'otally lmounte'd onthe other end of said bellcrank lever, and'a 'clampingscrew in said bifurcated clamping device .for engaging a, work piece to move itina 'direction perpendicular to said otherlwork engaging abutment, saidlinkage connectionbetween said clamping arm and bifurcated clamping device serving to effect a simultaneous application ofrclamping pressure of said clampingarm and said clamping screw on a work piece in engagement with said fixed abutments in ,saidchucking device.

5 it/ALTER R. MEYER. 

